Multicolor cinematograph and other films



Jan. 29, 1929. 1,700,618

J. E THORNTON 'MULTICOLOR CINEMATGRAPH AND OTHER FILM.

.Original Filed May 5, 1924 'f/)fzso 12- u/fiiea i/e-l/e/ Illlllllilllllllll Figa.

Patented Jan. 29, 1929.

UNITED sra'res PATENT Qli'FlCl...

' t JOHN EDWARD THORNTON, OFV WEST HAMYPSTEAD, LONDON, ENGIAND.v

*MULTICOLOR* CINEMATOGRAPH A ND OTHER FILMS- Original application led May v5, 1924, Serial No. 711,254, and in Great Britain May 18, 1923. Dividedl and this application led November 3, 1925. Serial NQ. 66,603.

This invention relates to the manufacture and `production of, multi-color film-material of the. screen-filterv type but of special construction, for the production of -cinematograph or other varieties of color-picturesof either negative or positive form; andits chief characteristic consists in its having two screen-filters arranged side-by-side upon a lm of double-width or double-area, and with 'l0 double-area' of sensitive surface, for each complete color-picture record made on the sensitive film.

The purpose of the two filter-'screens for each color-picture is to enable the picture to l5 be formed'or constructed in two parts, as two half-pictures, one upon each half of the ilm area; each section or half-picture c ontaining only two of the colors and each being different in coloring from theother, the' complete set of colors beingrepresented on the one double-film by the two half-pictures.

The group of colors forming each picture may befour, all of which are different; or the group may comprise only three colors,

with one ofthe colors duplicated to appear in each half-picture in order to make up the group of four; in either case the colors 4form a complementary set or group.

This improved film-material 1s designed for the production of color pictures made as f described in my application, Serial No. 7.11,- 254, tiled May 5, 1924, ofwliich this application is a division, and in l'my applications, Serial Nos. 60,602 and 06,604, both filed November 3, 1925.

The invention will be described with reference to the accompanying drawings, in which Fgurel is a plan view ofa double width film material.

Figure 2 is a plan view, greatly'enlarged, of a portion of `the color screens adjacent to the center line and showing the two halves -form-edwith alternating lines in two different colors to give a four-color analysis,

Figure 3 is a similar vie-W in which one color is duplicated upon each half to .give a three-color analysis.

Figures 4, 5 and 6 are similar views of different patterns of Color screens.

Figure 7 is a section taken on line 7-7 of Figure 5 illustrating .a positive film material of half standard thickness and Adouble width having screen filters coated with matic emulsion.

panchro-v Figure 8 is a similar section of a negative either in narrowA strips or preferably as wide webs to be afterwards cut into narrow strips;

y and one Variety is manufactured with a transparent base or support of standard thickness for the productionlof negative pictures and another variety is made-with a base of only half standard thickness for the production of positive pictures; otherwise the characteristics of both Varieties are identical.

I will now describe the construction and manufacturing methods as applied to the production of continuous strips of film for cinemajograph pictures, in which the two screens are placed side-by-s'ide upon a double-width strip, (Fig. 1) which may have been formed of that width or as a wide web from which it has' been cut after completion of all the manufacturing processes.

The same description will apply substany tially to the manufacture of non-cinematograph material with the difference only of size or area of the base and its nature and thickness.

llI/.mufactwc of the se'nn'il'z'fve negative' flmmaterial.

The negative-film-material (Fig. comprises four separate and different layerswhich are all so indissolublyY united that they form one homogeneous strip. The layers -material with a thickness of about .00005 inch.

(3) A screen-layer of suitable `colloid material with a thickness of about .00040 inch in or upon which are formed two screenfilters side-by-side. l

(4) An image layer of gelatino-silver-bromide panchromatic emulsion with a thickness of about .00100 inch.

` thickness of about .00600 inch, but it will be l 'Manufacture 0f the sensitive The above arrangement of layers produces a sensitive negative-iilm-material with a total which are all so indissolubly united that they form on'e homogeneous strip. `These different layers are formed in the order and of th composition as follows z- (l) A base or support of transparent waterproof material such as Celluloid, celluloseactateor the like, with a thickness of about .00150 inch.

(2)l A substrat-um of permanently adhesive `material with a thickness of about .00005 inch.

(3) A screen-layer of'suitable colloid material with a thickness of about .00040 inch in or upon which are formed two screen-filters side-by-side.

(4) An image' layer of gelatino-silver bromide panchroma'tic emulsion with a thickness of about .00100 inch.

The above arrangement of layers produces a sensitive positive-lilmmaterial with a total.

thickness of about .00300 inch, but it will be understood that these figures are approxi# mate,'being given as an illustration and not' as a limitation.`

F or positive-film-material the sensit-ive emulsion used is preferably of much slower speed than used for negatives and of very fine grain.

I nufacture of reinforced positive-#Zm- .material y The thin positive-iilm-material (Fig. 9)

y above described requires'to be printed, developed, or otherwise treated with great care, owing to the fact that it is only half the standard thickness and therefore liable to damage during the rough handling often given in the film printery.

This objection can however be overcome by constructing the positive film-material with the addition of a self-contained but `temporary reinforcing-strip of porous paper, upon which it is built or to which it is separatelyA attached during the process of manufacturing the film-material itself. This reinforcing strip is removed and thrown away when the two section-films have been developed, or at any other convenient stage of the process of producing the color-positive.

- Each section of such positive film-material will therefore comprise six layers, instead of -tached to layer 6.

. four asin the rst example, arranged in the* following order z- (l) A base or support of transparent wa. terproof material such as celluloid or the like, with `a thickness of about .00150 inch.

(2) A substratum of permanently adhesive materi'al'with a thickness of about .00005 i Y* inch.

(3) A screen-layer of suitable colloid ma.

terial with a thickness of about .00040 inch in or upon which are formed the two-color filterscreens. s

(4) An image vlayer of gelatino-silver bromide panchromatic emulsion with a thicknessof about .00100 inch and slightly lhardened during manufacture.

(5) A porous colloid layer, such as very soft easily soluble gelatine, glue, or the like, Vfree from alum -or other hardening agent, with a thickness of about .00050 inch, at-

, (6)k `A temporary reinforcing strip of porouspaper of about .00250 inch thick, attached to layer 5. l In manufacturing this reinforced Afilmmaterial the process of manufacture is divided so that the two separate parts A and B of i the complete material are first separately formed and afterwards combined and Vamalgamated to produce only one strip at a later i stage of the manufacture.

The first part A of this strip therefore comprises only layers l, 2, 3 and 4.

The second 5 and 6.

The two parts A and B are separately manpart B comprises only layers' ufactured and preferably before drying eachA is coated with a very thin adhesive substratum of porous, soluble, glue, t-he `onecoating upon face .4 and tbe other coating upon face 5. Each of these soluble adhesive substra tumlayers need only be about..00005 inch -thick. Alternativelythey may be applied when each film-part is dry. 'A But in eithermethod of application the two film-parts A and B are dried after application of the two soluble adhesive substratums.

The two soluble adhesive substratums of. the two film-parts A and B are next' slightly moistened, then brought into face-contact by rolling pressure, applied until the two substratums have produced a perfect and indissoluble union of the ytwo faces 4 and 5 of the film-parts A and B, so that a compound film is produced comprising the parts A and B with their layers l to 6.

The porous layer 5 performs a double function. adheres tenaciously to the grain or protuberances of the paper surface, and secondly as a filler by which the-depressions formed by the grain can be filled up level and a perfectly .smooth top surface obtained on the paper.

If necessary 'a second application may be made.- Therefore, owing to the smooth sur- Firstly, it serves as an adhesive which face of this layer no paper-grain is reproduced upon the picture when the printed image is developed. v The vrelative degrees of slight hardness of the layers 2, 8, 4 are so adjusted during manufacture that they will not dissolve when 'a suitable liquid is applied to dissolve the soluble adhesive substratums when it is desired to remove the paper layer (S and its adhering porous layer after the film is developed.

The above process produces a film material with a total thickness of about 1.00500 inch, which can be handled with safetyl during the Various processes in the film printery, but

may be increased by use of a thicker' paper layer 6.

Pan-@hremuteng the film-material.

In each of the foregoing varietiesof sensitive `film-material the panchroinatic dyes may be applied to the film in the emulsion itself,

. or preferably by soaking in baths after drygiven hereinafter.

ing the coated emulsion; or they may even be applied through the outer paper reinforcing strip.

I Screen-filters' for four-color pictures.

The filter-screen for four-color consists of an immense number of exceedingly fine colored dots, lines or mosaic pattern, (Figs. 2, 4 and 5) a fuller description of which is These are arranged in two groups, side-by-side upon the two halves of the double-'width film strip. One section consists of dots, lines. or other pattern of two colors equally intermixed, and the other section of two other colors equally' interinixed.

` The colors used for a four-color screen-filter (Figs. 2, 4 and 5) set are preferably crimsonred and blue-green for one half ofthe doublewidth negative film, and blue-violet and orange-yellow for the other half. These .form one filter set containing the comple'- inentary colors of red and green, and another filter-setcontaining the complementary colors of blue and yellow. Each half of the Screen-filters forthpee-color pictures;

The .filter-screen for three-color is of a similar character consisting of fine dots, lines, or mosaic pattern, but the colors comprise 'only crimson-red, blue-green, and blue-violet (Figs. 3 and 6) andare therefore only semicomplementary. They are arranged in two groups, one upon each half of the doublewidth film as in the preceding example, but

Manufacturing theZter-screens for both negative and positive ms.

The formation of the color-screens uponthe film base may be carried out by a number of knownv processes, but I prefer to use one of the following methodsv according to whether the accidental irregular dot-grain -is required, (Figs. 5 and 6) or a regular linescreen pattern (Fig-4) is preferred. The screen is similar for both negative vand positive kinds of film.

Of the great vnumber of screen-forming processes hitherto designed by investigators most are very expensive to produce, if three,

' four, or greater number of colors are required,

and lusually it is exceedingly difficult to secure uniformityl throughout `continuous lengths of cinematograph film by anymethod s heretofore used.

The methods of manufacture hereinafter described are very simple, the results reliable, and they permit of readily manufacturing unlimitedlengths of screen film at low cost.

These difficulties are tremendously reduced in this film by reason of thefact that each of. its sections contains only two colors, which are muchfeas-ier toA make than three or four, the four colors being obtained by the combined use .of twojsuch sections. The eitpense'and trouble accruing from differential blocking out and differential dyeing (as in old-style filter-screens) is tremendously reduced, the labour required being less than half.

For four-color one half the double-width film will therefore possess a screen-pair of two complementary colors, and the other half a similar screen-pair, but of different coinplementary colors, thus forming` .a quadrate (Figs. 2, l and 5).

For three-color one of the colors vis repeated upon both halves, as hereinbefore described in detail, thus 'forming a triad (Figs. 3 and 6).

The color-screens of both the negative and positive filins are manufactured by the same y methods.

Irregular-Zot filter-Screens produced nonphotograpkz'caly.

The double-width Celluloid or similar filmbase (Fig. l) is coated with the substratumlayer 2 and next with the screen-layer 3' (Figs. 7, 8 and 9). Before the latter is dry and hard .spaces between the insoluble dye grains; l' The 'film is next dried, andthe panchromatic` emulsion superimposed thereon lin any known manner.

Regular Zine 01k"` mosaic #Zier-screens produced p-zot'ographz'caZly.

y To produce regular-pattern screens I pre# fer photograph printing methods, of which two formsstand above all others for simplicity of manufacture.

In the first of these .methods the Celluloid base is first coated with its substratum-layer 2 and then with its screen-layer 3 (Figs. 7, 8 and 9). This layer consists ofv gelatine, albumen or other4 suitable' colloid containing a suitable mordanted dye.' After drying it is sensitized -inabichromate bath, or a suitable bichromate may b e mixed Awith a suitable dye and with thecol'loid, the mixture being next appliedv tothefilm'fin a layerof even thickness and correct depth. The dyes used are of differentcolors foreach screen upon each half-Width. i

The film-(Fig. 4) is next printed under a i line-screen of very fine range, say from 500 to 1000 to the inch, 'printing being preferably effected by .exposure to mercury-lamp tubes. I

The film is'next well washed until all dye is removed' from the soft non-printed colloid,

mordanting dyes have been used.

leaving behind the insoluble colloid in which.l the remaining dye is imprisoned.v

The film is next dried and is next subjected A'to a further dye bath that will color only the soft gelatine and leave the insoluble 'dyed portions untouched.

The dye last applied is next subjected to a mordanting' bathto fix the 'color unlessself- The panchromatic sensitive emulsion is next applied in the usual way.

In the second method silver-sensitized lm is used upon which to print the screen, and has the advantage of quicker printing. After development the line-printed film (Fig. 4) is treated in a bath which renders the lines insoluble in proportion to the deposit of metallic 'silver, thus producinga condition of insoluble colloid and enclosed dye similar to the bichromate example. The second dyeing is already described.

Irregular-dot #Her-screens produced photographically.

By using a negative printing clich covered with fine irregular dots of opaque substance suitably scattered, and printing by `either ythe -first "or second (photographic) method; orby making such anegative by reduction from a master clich having larger l grains, a'negative with very fine dots (Figs.

5 and 6) is secured; photographically printed color screens canv thus be made with the ,ir-

'regular dot formation. j l' With thephotographic methods described all differential printing and blocking-out are abolished, the process for a four-colorresult being reduced to one exposure and one dyeing for each half the double-width film, the two screen-halves being produced side-by-side simultaneously. What I claim as my invention and desire to protect by Letters Patent is l. A strip of film material for the production of color pictures comprising a trans-V parent support having two filter-screens arranged side-by-side, one screen having two colors and the other screen having two other colors, anda la yer of panchromatic emulsion covering said screens.

2. A strip of film material for the production of color pictures comprising a transparent support having two color filter-screens arranged side-by-side on the same face thereof, each screen containing two colors, and a layer of pan'chromatie'emulsion 'and covering said screens.

3. A strip of film material for the produc-v tion of color pictures comprising a transapplied.` to

parent support of doublepicture area having i two color filter-screens arranged on its respective picture-areas, each screen containing two colors, the colors of one screen being different from those of the other screen, and

a layer of panchromatic emulsion covering said screens.

4. A strip of film material for the production of color pictures comprising a transparent support of double picture-area in 'width and having two color filter-screens arranged on the same face and on the respective areas thereof, each screen cont-ainingtwo colors, the colors of one screen being different from those of the other screen and a layer of panchromatic emulsion covering said screens.

5. A continuous strip of cinematograph .film material for the product-ion of color perforated film material for the production of color pictures of the screen-filter class in series, comprising a double-Width strip of transparent waterproof material, a layer of adhesive sub-stratum superimposed upon and amalgamated with said strip, two screenlters formed side-by-side, one upon each half-Width of the strip and united with the substratum thereon, each screen consisting of two complementary colors, said screens forming a complementary sot of color-analyzers, and a layer of rapid` panchromatic emulsion superinlposed upon and unitedto I the-scrcentilters, the whole forming a comforming a set of color-analyzers, and avlayer' 4 t ofpanchromatic emulsion united to the screen-Elters. l

8. A strip of film material of the class describe d comprising a transparent flexible sup- -port 'having .color filterfscreens on a face thereof, a layer of sensitive emulsion covermg sald screens, and a :flexible reinforcing strip removably applied tol thelayer of sen-.-l

sitive emulsion.

9. A strip ofv film material of the class described comprising a transparent flexible support having color ilter-screens'on a face thereof, a layer of sensitive emulsion `covering said screens, a flexible reinforcing strip,

and an easily soluble mediuinuniting said 'Y reinforcing strip with said layer of emulsion.

10. A strip of lilm material of the class described comprising a transparent flexible support having color filter-screens united to a face thereof, a layer of sensitive emulsion covering saidy screens, said emulsion being exposable through the support and the filterscreens, and a reinforcing strlp-attached to .the layer' of 'emulsion and removabletherefrom after exposure of the emulsion;

11. A temporarily reinforced continuous strip of lilm material for the production of" color pictures of the screen-filter class in series, comprising Aa double-Width stripof" transparent 'Waterproof material, a layer of adhesive substratum superimposed upon and amalgamated with said strip, two screen-tilters formed side-by-side upon the strip and united to said substratum thereon, one screenfilter occupying each half-,Width of the strip and each screen consisting of two complementary colors, said screensl form-ing a set of color-analyzers, a relatively. hardened layer of panchromatic emulsion covering and uni-ted to the screen filters, a relatively soft porouscolloid layer attached to saidlayer of emulsion, and a reinforcing strip .of porous paper attached to the 'softcolloid layer;

In testimony whereofl vhave-hereunto set my hand.

JOHN EDWARD THORNTON.. 

